Hey everyone, I'm new to this site. I came across it after trying to figure out some issues I've been having with my '01 24v and am hoping someone could provide me with some insight. Now here's the problem:Today I was driving my '01 24v (mods in signature) and everything was perfectly normal. I then shut it off and about two hours later started it up. When I started it up again, the water temperature gauge, oil pressure gauge, and tach were all not working. The truck was running and idling perfectly fine and the check engine light did not come on. I did notice that when I turned the key to the start position, the oil pressure and water temperature gauge both twitched, so I know they definitely have power. But just incase, I checked all of the fuses and all were good. I then checked for codes and got a P1694 code, which came up as "Fault In Companion Module." So now I'm beginning to think it's the ECM. I'm really hoping I'm overlooking something that may possibly be faulting the computer. Any ideas or input? Thanks in advance.

there's another post on here somewhere about the same issue, I had the same thign a couple years ago. Wierd as it sounds, if I turned the headlights on and put them in high beam, all the gauges came back, put them in low and they dropped off again,I tried another cluster but the same thing happened . Went away on it's own after a while both times it happened and knock on wood hasn't happened since.

Thanks! I will give that a try and see what happens. Oddly enough, just about all of the very limited amount of info I could find on this problem concluded that after a day or two, the problem just went away. Some people people said it occurred again after 10 months or so, and others said after it went away, it never came back. I also saw an instance where the bolt on the main bus power feed in the under hood fuse panel was loose, and after being tightened, the problem went away. So I'll give all of this a try and hopefully something will work!

Try the cluster testing... http://mopar.mopar1973man.com/cummins/2ndgen24v/cluster/cluster.htm

Well I have good news and bad news. The good news is I have my gauges back! It turned out to be a loose main bus power feed. When I checked the under hood fuse panel yesterday, I didn't pay too much attention to it. When I looked everything over again today, the bus power feed was very loose; I could turn the screw that clamps it down by hand. Either the screw or the threads in the hole are stripped, as the screw will keep spinning, but I got it tight enough to work for now. I still need to work on a permanent fix though.Now the bad news: After the gauges were back to normal, I noticed the check engine light came on while taking it for a test drive. The truck was running perfectly normal. I came back and checked the codes and got the following:P PCU:P 1694 (Same Code as before)P 1093P ECUP 0237P 1698I then disconnected the batteries to clear the codes. After letting it sit for 15 minutes or so, I reconnected the batteries only to find the CEL still on. So I checked for codes again and this time I got the following:P PCUP 1693P ECUP 0237P 1698So now I don't now which route to take to get the CEL off. The truck is running absolutely flawless. It idles fine and runs smooth. I'm not overly concerned about the CEL but I would like to get it off. Any ideas?

Sounds like you still got some loose connections. Might go through and check everything. 0237 is low input turbo boost and the other has to do with not getting data from PCM. Probably all stems from the PCM having a loose connection so check all that again.

Thanks, I'll go through and check everything. From just a quick search, I saw some people cleaned/replaced the MAP sensor after getting the 0237 code and it alleviated any problems. Coincidentally, most of those same people were also running an Edge Comp box as well. I'm still making the same amount of boost as before and the truck runs just like normal. I think I'll check all of the connections and then disconnect the Comp box and then disconnect the batteries. Hopefully it is something simple.

---------- Post added at 03:53 PM ---------- Previous post was at 11:45 AM ----------

Well the CEL turned off on it's own and everything is back to normal, I cleared the codes and am no longer having any issues. So now I'm just hoping it stays this way.

as mopar1973man has shown...disconnecting batteries does NOT clear the CEL...you have to use a code reader...any generic one should do.

as mopar1973man has shown...disconnecting batteries does NOT clear the CEL...you have to use a code reader...any generic one should do.

Make sure you disconnect again and do the APPS calibation procedure... Because anytime you pull the batteries you wipe out the APPS setting... The error code will remain for 40 warm up cycles. The CEL light normally goes out in 3-5 key cycles. This information is all stored in non-volatile memory so you could basically disconnect the batteeries for 10 years and the codes will be there again after 10 years...

---------- Post added at 08:35 AM ---------- Previous post was at 08:30 AM ----------

Well I have good news and bad news.

The good news is I have my gauges back! It turned out to be a loose main bus power feed. When I checked the under hood fuse panel yesterday, I didn't pay too much attention to it. When I looked everything over again today, the bus power feed was very loose; I could turn the screw that clamps it down by hand. Either the screw or the threads in the hole are stripped, as the screw will keep spinning, but I got it tight enough to work for now. I still need to work on a permanent fix though.

Now the bad news: After the gauges were back to normal, I noticed the check engine light came on while taking it for a test drive. The truck was running perfectly normal. I came back and checked the codes and got the following:

P PCU:

P 1694 (Same Code as before) No CCD Messages received from ECM Bus communication failure to PCM.

P 1093 DTC Detected in PCM/ECM or DTC Detected in ECM A Companion DTC was set in both the ECM and PCM.

P ECU

P 0237 Map Sensor Voltage Too Low MAP sensor voltage input below the minimum acceptable voltage.P 1698

I then disconnected the batteries to clear the codes. After letting it sit for 15 minutes or so, I reconnected the batteries only to find the CEL still on. So I checked for codes again and this time I got the following:

P PCU

P 1693 DTC Detected in PCM/ECM or DTC Detected in ECM A Companion DTC was set in both the ECM and PCM.

P ECU

P 0237 Map Sensor Voltage Too Low MAP sensor voltage input below the minimum acceptable voltage.

P 1698 No CCD Messages received from PCM Bus communication failure to PCM. A Companion DTC was set in both the ECM and PCM.

So now I don't now which route to take to get the CEL off. The truck is running absolutely flawless. It idles fine and runs smooth. I'm not overly concerned about the CEL but I would like to get it off. Any ideas?

As for you post... Comment in blue...

Make sure you disconnect again and do the APPS calibation procedure... Because anytime you pull the batteries you wipe out the APPS setting... The error code will remain for 40 warm up cycles. The CEL light normally goes out in 3-5 key cycles. This information is all stored in non-volatile memory so you could basically disconnect the batteeries for 10 years and the codes will be there again after 10 years... As for you post... Comment in blue...

Thanks for the info! My truck is still running good and the gauges have remained since tightening the BUS power feed. Everything else is still in check. I appreciate the quick responses everyone!